Norfolk police say the couple found dead in the river between Salhouse Broad and Wroxham Broad are believed to be from Surrey.
Home Office post mortems have begun at the James Paget Hospital.
A 13 year old girl found alone on board the family's hire boat is being supported by family members.
Our main consideration is the welfare of the 13-year-girl and whilst I cannot speculate on the circumstances surrounding the deaths before I have received the results of the post mortems, initial investigations confirm that we are not looking for anyone else in connection with the incident."
– Det Supt Jes Fry, Norfolk and Suffolk major investigation team
Officers cordoned off a stretch of the River Bure after a 13-year-old girl was found alone on a rented boat on Saturday. They found the bodies of the couple in the river on Sunday.
The woman's believed to be the girl's mother, the man's been described as her partner.